Ferroelectric varactors suitable for capacitive shunt switching

Abstract

An embodiment of the present invention provides an apparatus, comprising a radio frequency switch capable of using tunable dielectric capacitors as the switching element for a plurality of cross connected ports. Further, the RF switching may be accomplished by creating an RF short at a tee within said apparatus by the combination of transmission lines and the impedance provided by the tunable dielectric capacitor.

1. An apparatus, comprising:
 a radio frequency switch capable of using tunable dielectric capacitors as a switching element for a plurality of cross connected ports; 
 wherein RF switching is accomplished by creating an RF short at a tee within said apparatus by a combination of transmission lines and an impedance provided by at least one of said tunable dielectric capacitors. 
 
   
   
     2. The apparatus of  claim 1 , wherein at least one of said tunable dielectric capacitors is placed between a cross connector and least one of the plurality of cross connected ports, thereby enabling impedance variation between said cross connector and said least one of the plurality of cross connected ports. 
   
   
     3. The apparatus of  claim 2 , further comprising at least one tee connector between said cross connector and at least one of said plurality of ports, wherein at least one of the tunable dielectric capacitors is associated with said at least one tee connector to vary the impedance in at least one node of said at least one tee connector. 
   
   
     4. The apparatus of  claim 3 , wherein said at least one tunable dielectric capacitor associated with said at least one tee connector is associated by using a plurality parallel switching sections in paths. 
   
   
     5. The apparatus of  claim 4 , wherein said plurality of parallel switching sections is two parallel switching sections. 
   
   
     6. The apparatus of  claim 2 , wherein said impedance variation enables RF signal control to any of said least one of the plurality of cross connected ports. 
   
   
     7. An RF Switch, comprising:
 an input port; 
 a plurality of output ports; and 
 wherein said RF switch switches between said plurality of output ports by creating an RF short at a tee within said RF switch by a combination of transmission lines and an impedance provided by at least one tunable dielectric capacitor. 
 
   
   
     8. The RF Switch of  claim 7 , further comprising a cross connector connecting said plurality of output ports. 
   
   
     9. The RF Switch of  claim 8 , further comprising and at least one tee connector between said cross connector and at least one of said plurality of output ports, wherein said at least one tunable dielectric capacitor is associated with said at least one tee connector to vary the impedance in at least one node of said tee connector. 
   
   
     10. The RF Switch of  claim 9 , wherein said impedance being varied enables RF signal control to any of said plurality of output ports. 
   
   
     11. The RF Switch of  claim 9 , wherein said at least one tunable dielectric capacitor associated with said at least one tee connector is associated by using a plurality parallel switching sections in paths. 
   
   
     12. The RF Switch of  claim 11 , wherein said plurality of parallel switching sections is two parallel switching sections. 
   
   
     13. A method, comprising:
 increasing isolation of inactive paths in a multi-way switch by using a plurality of parallel switching sections in each of said inactive paths of the multi-way switch, said parallel switching sections including tunable capacitors capable of high isolation by varying control voltages to said tunable capacitors. 
 
   
   
     14. The method of  claim 13 , wherein said multi-way switch is a three-way switch and said plurality of parallel switching sections is two parallel switching sections in each of said inactive paths of said three-way switch.